Suppression of alien crosstalk in communication systems is an increasingly important practice for improving systems' reliability and the quality of communication. As the bandwidth of communication systems increases, so does the importance of reducing or eliminating alien crosstalk.
In wired communication systems, crosstalk is caused by electromagnetic interference within a communication cable or between cables. Crosstalk coupling between pairs is proportional to the dielectric constant of the material separating the two pairs. Therefore, decreasing the overall dielectric constant of the material between the conductors decreases the crosstalk between the pairs. There will also be a resulting decrease in alien crosstalk between adjacent communication cables having decreased overall dielectric constants for the materials separating the conductors.
The dielectric constant is a key parameter in the construction of high performance cable. It can be inversely proportional to the signal throughput and directly proportional to the attenuation values when the cable design is properly optimized. Generally, as the dielectric constant decreases, the signal throughput increases and the signal attenuation values decrease—all attributed to the cable dimensional design that can be more favorably optimized. Thus, a lower dielectric constant can result in a stronger signal arriving more quickly with less distortion and less delay skew.
Therefore, there is a need to reduce the overall dielectric constant of the material that separates conductors in a cable in order to reduce crosstalk and delay skew and provide stronger, less attenuated signals.